To meet the demand for wireless data traffic having increased since deployment of 4th generation (4G) communication systems, efforts have been made to develop an improved 5th generation (5G) or pre-5G communication system. Therefore, the 5G or pre-5G communication system is also called a ‘Beyond 4G Network’ or a ‘Post LTE System’.
The 5G communication system is considered to be implemented in higher frequency (mmWave) bands, e.g., 60 GHz bands, so as to accomplish higher data rates. To decrease propagation loss of the radio waves and increase the transmission distance, the beamforming, massive multiple-input multiple-output (MIMO), Full Dimensional MIMO (FD-MIMO), array antenna, an analog beam forming, large scale antenna techniques are discussed in 5G communication systems.
In addition, in 5G communication systems, development for system network improvement is under way based on advanced small cells, cloud Radio Access Networks (RANs), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, moving network, cooperative communication, Coordinated Multi-Points (CoMP), reception-end interference cancellation and the like.
In the 5G system, Hybrid FSK and QAM Modulation (FQAM) and sliding window superposition coding (SWSC) as an advanced coding modulation (ACM), and filter bank multi carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) as an advanced access technology have been developed.
The concept of adding a large number of transmit antennas, often dubbed massive or large-scale multiple-input multiple-output (MIMO) systems, has been drawing considerable interest from both industry and academia over the past few years. To facilitate beamforming gain and/or spatial multiplexing gain of large-scale MIMO systems, channel state information (CSI) between a transmitter and a receiver is essential at the transmitter side. Time division duplexing (TDD) is often assumed in large-scale MIMO systems to rely on the channel reciprocity property to have the CSI at the transmitter side without pilot transmission and channel estimation/feedback phases. However, Frequency Division Duplexing (FDD) is difficult to acquire the CSI in reliance on the channel reciprocity property because of different frequency bands of both channels.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.